Traditional intensive care unit (ICU) and emergent care electrocardiograph (ECG) monitoring equipment is typically composed of a passive contact or non-contact patient interface lead frame, a passive hookup cable, and an active bedside monitor or similar piece of equipment that also performs the function of passing telemetry information acquired from the passive lead set into the monitoring infrastructure. In this case, the only active electronics in the system are contained within the bedside monitor function. Noteworthy is that the disposable or reusable patient leads and hookup cable are not responsible for actively monitoring, recording, or propagating the ECG information to displays, monitoring stations or other information technology (IT) infrastructure of the containing facility.
FIG. 1 is a schematic illustration of a wired ECG monitoring system. Electrical signal information from patient 102 is obtained at passive contacts 103a-c connected to the patient's body. Electrical signals are transmitted via patient leads 104a-c to hook-up cable assembly 106 and bed-side monitor 108, which limit the available space surrounding the patient's bed. Active electronics for performing measurement are found in bed-side monitor 108. Bed-side display 110 shows the measurement information obtained by bed-side monitor 108 for the use of clinicians who are in physical proximity to the patient. Measurement information may be sent from bed-side monitor 108 to an IT infrastructure 112, which may then send the information to a remote monitoring station, such as a nurse's station, or a patient telemetry database.
A similar technique is deployed by current existing wireless systems in the market, which simply deploy a more portable version of the bed-side monitor, where the bedside monitor is usually reduced in form-factor and worn as an accessory to the patient, either carried or affixed via adjustable strap or band:
FIG. 2 is a schematic illustration of a wireless ECG monitoring system. Electrical signal information from patient 102 is obtained at passive contacts 103a-c connected to the patient's body. The obtained electrical signals are transmitted via patient leads 104a-c to portable equipment 202, which contains electronics and equipment configured to enable wireless transmission of information to a bed-side display. Portable equipment 202 may contain substantially all the electronics previously found in hook-up cable assembly 106 and/or bed-side monitor 108. Wireless transceiver device 202 is physically affixed to the patient's arm using a simple arm band 204.
In the case of FIG. 2, the ECG monitor can be wirelessly connected via Wi-Fi packet-based data protocols or other wireless/radio-frequency (RF) technologies such as low-power Bluetooth to IT infrastructure and subsequent remote monitoring stations to propagate the patient data. The portable equipment 202 also makes use of passive disposable or reusable leads that connect the patient to the active electronics residing with the portable unit.
This overall passive lead/base station model is also used with oxygen saturation (SpO2)/pulse-ox (oximetry) vital monitoring systems that are typically used in a standard emergency room (ER)/ICU patient monitoring configuration.
These sensing techniques are relatively easy and cost-effective for health care institutions to implement.